Adaptive suspension height steering assistance method and eps dynamic assistance regulation system

Abstract

The application discloses a self-adaptive suspension height steering assisting method, which is implemented based on an EPS electronic assisting steering system and comprises the following steps: 1) collecting self-adaptive compensation calculation parameters in real time, and performing filtering and normalization processing on the parameters, so that the parameters are used to establish a segmented nonlinear compensation model; and 2) establishing a segmented nonlinear compensation model with multiple parameters coupling based on the collected parameters, and calculating to obtain a final assisting motor output torque. The coupling relationship between the suspension height change and the steering system is fully considered, and the self-adaptive suspension height adjusting steering assisting method guarantees the steering feeling consistency and the steering precision under the conditions of the suspension height adjustment, the vehicle load change and the like.

Description

Technical Field

[0001] This invention relates to the automotive field, and in particular to an adaptive suspension height steering assist method, and an EPS dynamic assist adjustment system for implementing the adaptive suspension height steering assist method. Background Technology

[0002] Electric power steering (EPS) is a core technology in modern automotive chassis control, and its power steering characteristics directly affect the driving experience and safety of the vehicle. Current EPS systems primarily adjust power steering based on two parameters: vehicle speed and steering wheel torque, using preset adjustment logic to change the torque output of the power steering motor.

[0003] In vehicles equipped with adjustable suspension systems such as air suspension, the suspension height adjusts according to driving conditions and load changes. This change in suspension height alters the relative position of the wheels and the vehicle body, leading to shifts in steering geometry parameters such as caster and camber angles, and consequently, changes in the steering ratio and return torque. When the air suspension is raised, the return torque increases, making the steering wheel feel heavier at low speeds; conversely, when the air suspension is lowered, the return torque decreases, making the steering wheel more prone to a "floating" sensation at high speeds and reducing steering precision. Research data shows that a suspension height change of ±50mm can cause a steering ratio fluctuation of 8%-12%, directly affecting the driver's accurate perception of the road.

[0004] The existing technology has the following technical problems that need to be solved: 1. The coupling relationship between the EPS system and the suspension system is fully considered, and the power assist is mismatched with the actual working conditions when the vehicle body posture changes.

[0005] 2. The sensor signal fusion and compensation algorithm lacks real-time performance, and the response delay exceeds 100ms, which can easily cause driving discomfort.

[0006] 3. Lack of functional safety redundancy and inadequate strategies in case of sensor failure.

[0007] 4. The suspension and EPS are controlled independently, without dynamic correction, making it impossible to fundamentally eliminate the impact of suspension height changes on steering feel. (Invention Content) The summary of this invention introduces a series of simplified concepts, all of which are simplifications of existing technologies in the field, and will be further explained in detail in the detailed description section. This summary is not intended to limit the key features and essential technical features of the claimed technical solution, nor is it intended to determine the scope of protection of the claimed technical solution.

[0008] To address the shortcomings of existing technologies, the technical problem solved by this invention is that existing EPS electronic power steering systems do not consider the coupling relationship between suspension height changes and the steering system. Under conditions such as suspension height adjustment and vehicle load changes, changes in steering geometry parameters lead to a decrease in steering feel consistency and insufficient steering precision. The EPS and suspension are controlled independently, the compensation algorithm has low accuracy and large response delay, and the existing system has problems such as poor real-time performance of signal fusion algorithm and lack of functional safety redundancy design.

[0009] To address the aforementioned technical problems, this invention provides an adaptive suspension height steering assist method, which is implemented based on an EPS electronic power steering system and includes the following steps: 1) Real-time acquisition of adaptive compensation calculation parameters, which are then filtered and normalized to establish a piecewise nonlinear compensation model; The adaptive compensation parameters include: vehicle suspension height change Δh, steering wheel torque signal, steering wheel angle θsw, driving speed v, road adhesion coefficient, vehicle lateral acceleration, kingpin dynamic geometric parameters, and vehicle load state dynamic parameters. 2) Establish a piecewise nonlinear compensation model with multi-parameter coupling based on the acquired parameters, including: The relationship between the driver's hand torque Td and the basic torque Ta of the power steering motor is as follows: Td=(Tr-Ta×i×η) / G;Tr is the steering resistance torque, i is the reduction ratio, η is the transmission efficiency, and G is the steering transmission ratio; The formula for calculating the change in steering ratio ΔG caused by the change in suspension height Δh is: ΔG / G≈k×Δh×sin(α); k is the suspension stiffness coefficient, and α is the kingpin inclination angle; Based on the road adhesion coefficient μ, lateral acceleration ay, kingpin dynamic geometric parameter γ / σ, and load state m as correction factors, the steering resistance torque Tr is dynamically corrected. The correction formula is as follows: Trcorr=Tr×[1+kμ×(1−μ)+kay⋅ay+kγ×∣Δγ∣+km×Δm]; kμ, kay, kγ, and km are the correction coefficients calibrated on the actual vehicle, Δγ is the dynamic offset of the kingpin caster angle, and Δm is the load change. The final output torque of the boost motor is: Tacomp = Tabase × f(Δh,v,ay,m) × kμ × kσ; Tabase is the basic assist torque of EPS, f(Δh,v,ay,m) is the four-dimensional coupling compensation function, and kσ is the steering shaft tilt correction coefficient.

[0010] Preferably, the adaptive suspension height steering assist method further includes: The final total boost gain coefficient is determined by querying the multidimensional coupled MAP graph for boost compensation, and then constrained by piecewise nonlinear interpolation.

[0011] Preferably, the adaptive suspension height steering assist method is further improved by constructing a four-layer multi-dimensional coupled MAP, including: calibrating a four-layer coupled MAP covering all operating conditions through real vehicle testing, with each MAP layer being two-dimensional and nested and coupled layer by layer. First layer: Suspension height Δh - vehicle speed v maps to basic power assist gain coefficient k1; Second layer: Lateral acceleration ay-load state m mapping dynamic correction coefficient k2; Third layer: Road surface adhesion coefficient μ-king pin back tilt angle γ mapped to road surface geometric correction coefficient k3; Fourth layer: Steering wheel angle θsw - steering shaft tilt σ mapped to geometric correction coefficient k4; The final total boost gain coefficient k = k1 × k2 × k3 × k4.

[0012] Preferably, a further improvement to the adaptive suspension height steering assist method includes piecewise nonlinear interpolation comprising: dividing each MAP map into segments according to vehicle driving conditions: Low speed range: v≤30km / h; Medium speed range: 30km / h <v≤80km / h; High-speed section: v>80km / h; Each segment employs quadratic polynomial nonlinear interpolation to make the power assist gain more closely match the nonlinear characteristics of actual steering resistance as parameters change; Preferably, the adaptive suspension height steering assist method is further improved by setting the interpolation slope constraint to ≤0.05 / ms.

[0013] Preferably, the adaptive suspension height steering assist method is further improved by adjusting the kingpin dynamic geometry parameters in the following way: The suspension ECU calculates the dynamic offset of the kingpin caster angle γ and the steering shaft tilt σ in real time based on the collected control arm angle, and controls the kingpin caster trail within a first distance range of -10mm to +5mm and the steering shaft tilt within a first angle range of -1° to +3° through the air suspension actuator (inflation / deflation valve, control arm micro-adjuster).

[0014] Preferably, the adaptive suspension height steering assist method further includes: The steps for suspension-EPS bidirectional synchronization include: while adjusting the suspension height and kingpin dynamic geometry parameters, the suspension ECU sends a pre-compensation command to the EPS ECU via the CAN FD bus, and the EPS ECU adjusts the power assist gain in advance; The EPS ECU feeds back the working status of the steering system to the suspension ECU in real time. The suspension ECU then dynamically adjusts the suspension damping based on the feedback, achieving two-way coordination.

[0015] This invention provides an EPS dynamic power steering adjustment system for implementing the adaptive suspension height steering assist method described in any of the above-mentioned methods, comprising: a distributed multi-sensor redundancy group, a suspension ECU, an EPS ECU, a CAN FD bus, an air suspension actuator, and an EPS power assist motor; the distributed multi-sensor redundancy group includes a suspension height sensor, a vehicle speed sensor, a steering wheel torque / angle sensor, an ESP inertial measurement unit (IMU), a tire pressure sensor, and an integrated suspension height-sway arm angle sensor; The distributed multi-sensor redundancy group is connected to the suspension ECU and EPS ECU via CAN FD bus; The suspension ECU is connected to the air suspension actuator to collect suspension height and control arm angle signals, calculate kingpin dynamic geometric parameters, and control the air suspension actuator. The EPS ECU is connected to the EPS booster motor and is used to receive multi-dimensional parameters, run a piecewise nonlinear compensation model and a multi-dimensional coupled MAP graph interpolation algorithm, and output control signals to the EPS booster motor.

[0016] Preferably, the adaptive suspension height steering assist method is further improved by including a distributed multi-sensor redundancy group comprising a suspension height sensor, a control arm angle sensor, a vehicle speed sensor, a steering wheel torque sensor, a steering wheel angle sensor, an ESP inertial measurement unit, and a tire pressure sensor.

[0017] Based on the above technical solution, the working principle of the present invention is explained as follows: The core working principle of this invention is based on the coupling relationship between suspension kinematics and steering dynamics: when the vehicle body height changes due to load changes or air suspension adjustment, the angle between the steering tie rod and the suspension control arm will change accordingly, directly causing the steering transmission ratio, steering return torque, kingpin caster angle, steering shaft tilt and other steering geometric parameters to shift, thereby changing the steering resistance torque and driver feel.

[0018] This invention uses a distributed multi-sensor redundancy group to collect real-time parameters such as suspension height, vehicle speed, steering wheel torque / angle, road adhesion coefficient, lateral acceleration, kingpin dynamic geometric parameters, and vehicle load status. These parameters are then transmitted at high speed to the suspension ECU and EPS ECU via the CANFD bus. Based on these signals, a piecewise nonlinear compensation model of "suspension kinematics-steering dynamics" with multiple parameters is established. The assist gain coefficient adapted to the current operating conditions is calculated by combining a four-layer multidimensional coupled MAP diagram with piecewise nonlinear interpolation. Simultaneously, the suspension ECU actively corrects the kingpin geometry parameters and sends a pre-compensation command to the EPSECU via the CAN FD bus, so that the EPS power assist motor outputs a power assist torque that is precisely matched with the current suspension height, vehicle posture, and driving conditions. Ultimately, the suspension geometry adjustment and steering assist compensation are executed synchronously, maintaining a high degree of consistency in steering feel under all vehicle postures.

[0019] Based on the above technical solution and working principle, the present invention can achieve at least the following technical effects compared with the prior art: 1. Existing EPS systems only adjust power assist based on vehicle speed and steering wheel torque, without establishing a coupling model between the suspension system and the steering system, and without compensating for the deviation of steering geometry parameters caused by changes in suspension height, resulting in a mismatch between power assist characteristics and actual steering requirements.

[0020] When the suspension height changes by ±50mm, this invention can offset 8-12% of the steering ratio fluctuation through steering ratio correction and power assist torque compensation. Regardless of whether the suspension is raised or lowered, the driver's steering feel remains consistent, with light steering at low speeds and stable steering at high speeds without any "floating" phenomenon. Therefore, this invention can achieve consistent steering feel under different vehicle postures and eliminate the impact of suspension height changes on the steering experience.

[0021] 2. Existing sensor signal fusion and compensation algorithms lack real-time performance, do not employ bus-based real-time communication and lookup table-based fast correction strategies, and have response delays that easily exceed 100ms, making them unsuitable for real-time compensation requirements for dynamic changes in suspension height.

[0022] This invention enables real-time communication between the suspension ECU and EPSECU via the CAN bus. Combined with a built-in fast compensation algorithm and a two-dimensional lookup table to output correction coefficients, it significantly improves the response speed of signal fusion and compensation, eliminating driver discomfort caused by response delays. Therefore, this invention enhances the real-time performance of sensor signal processing and avoids driver discomfort. 3. Existing technologies lack functional safety redundancy design, do not have a multi-sensor redundancy architecture, and do not have a sound sensor failure degradation strategy. Sensor failure can easily lead to power steering adjustment failure, affecting driving safety.

[0023] This invention employs a multi-sensor redundancy architecture utilizing torque, steering angle, and suspension height sensors. The system design meets ISO26262 ASIL-C functional safety requirements. Even if a single sensor fails, the system can degrade its operation through redundant signals, ensuring the basic function of steering assist adjustment. Therefore, this invention satisfies functional safety requirements and improves the stability and reliability of system operation.

[0024] 4. In the existing technology, the suspension system and EPS system are independent systems with no data interaction and coordinated adjustment logic. They can only adjust the suspension or power assist individually and cannot control the source of the error of attitude change or provide residual compensation.

[0025] The suspension ECU actively adjusts the damping characteristics to reduce vehicle body posture changes at the source, while the EPS ECU synchronously compensates for residual errors. This dual adjustment method makes the power assist torque correction more precise, further optimizing the accuracy of steering feel. Therefore, this invention enables coordinated adjustment of the suspension system and the EPS system, improving the accuracy of power assist compensation. 5. Existing technology uses a uniform range of power assist adjustment coefficients and does not differentiate the working conditions of power assist compensation caused by suspension height in combination with vehicle speed, thus failing to meet the different steering needs at low and high speeds simultaneously.

[0026] This invention employs a segmented compensation coefficient range design. At low speeds, a wide range of compensation ensures light steering operation, while at high speeds, a narrow range of compensation limits the range of power steering adjustment, ensuring steering stability and precision during high-speed straight-line driving. Therefore, it can adapt to the steering requirements of different driving conditions, balancing low-speed steering agility with high-speed driving stability. Detailed Implementation

[0027] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can fully understand other advantages and technical effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through different specific embodiments, and various details in this specification can also be applied based on different viewpoints, with various modifications or changes made without departing from the overall design concept of the invention. It should be noted that, in the absence of conflict, the following embodiments and features in the embodiments can be combined with each other. The following exemplary embodiments of the present invention can be implemented in many different forms and should not be construed as being limited to the specific embodiments set forth herein. It should be understood that these embodiments are provided to make the disclosure of the present invention thorough and complete, and to fully convey the technical solutions of these exemplary embodiments to those skilled in the art. It should be understood that when an element is referred to as "connected" or "combined" to another element, the element can be directly connected or combined to the other element, or there may be intermediate elements. The difference is that when an element is referred to as "directly connected" or "directly combined" to another element, there are no intermediate elements.

[0028] The embodiments of the present invention include method embodiments and system embodiments. The system embodiments are the hardware and software architecture foundation for implementing the method embodiments, and the method embodiments are the specific operation flow of the system embodiments. The two correspond to each other and work together to achieve adaptive suspension height steering assist adjustment.

[0029] First embodiment; This invention provides an adaptive suspension height steering assist method, which is implemented based on an EPS electronic power steering system, and includes the following steps: 1) Real-time acquisition of adaptive compensation calculation parameters, which are then filtered and normalized to establish a piecewise nonlinear compensation model; The adaptive compensation parameters include: vehicle suspension height change Δh, steering wheel torque signal, steering wheel angle θsw, driving speed v, road adhesion coefficient, vehicle lateral acceleration, kingpin dynamic geometric parameters, and vehicle load state dynamic parameters. First, it should be noted that, compared to existing technologies, this invention takes into account the influence of dynamic parameters more comprehensively, and adds the following dynamic parameters: Road surface adhesion coefficient μ: estimated by fusing ABS wheel speed difference and ESP yaw rate deviation, requiring no additional hardware; Lateral acceleration of the vehicle: collected by the ESP inertial measurement unit (IMU), reflecting the vehicle's turning attitude; Kingpin dynamic geometric parameters (kingpin caster angle γ, steering shaft tilt angle σ): The swing arm angle is collected by the integrated suspension height-swing arm angle sensor and calculated in real time by the suspension kinematic model; Vehicle load status m: estimated by fusing signals from the suspension height difference of four wheels and tire pressure sensor, reflecting the no-load / full-load / partial-load status; 2) Establish a piecewise nonlinear compensation model with multi-parameter coupling based on the acquired parameters, including: The basic mechanical relationship between the driver's hand torque Td and the basic torque Ta of the power steering motor is as follows: Td=(Tr-Ta×i×η) / G;Tr is the steering resistance torque, i is the reduction ratio, η is the transmission efficiency, and G is the steering transmission ratio; The formula for calculating the change in steering ratio ΔG caused by the change in suspension height Δh is: ΔG / G≈k×Δh×sin(α); k is the suspension stiffness coefficient, and α is the kingpin inclination angle; Based on the road adhesion coefficient μ, lateral acceleration ay, kingpin dynamic geometric parameter γ / σ, and load state m as correction factors, the steering resistance torque Tr is dynamically corrected. The correction formula is as follows: Trcorr=Tr×[1+kμ×(1−μ)+kay⋅ay+kγ×∣Δγ∣+km×Δm]; kμ, kay, kγ, and km are the correction coefficients calibrated on the actual vehicle, Δγ is the dynamic offset of the kingpin caster angle, and Δm is the load change. The final output torque of the boost motor is: Tacomp = Tabase × f(Δh,v,ay,m) × kμ × kσ; Tabase is the basic assist torque of EPS, f(Δh,v,ay,m) is the four-dimensional coupling compensation function, and kσ is the steering shaft tilt correction coefficient.

[0030] Second embodiment; This invention provides a second embodiment of a method for adjusting steering assist based on suspension height, which is a further improvement on the first embodiment described above. The identical parts will not be repeated here, and it also includes: The final total assist gain coefficient is determined by querying the multidimensional coupled MAP graph for assist compensation, and the final total assist gain coefficient is constrained by piecewise nonlinear interpolation to improve the compensation accuracy. Constructing a four-layer multidimensional coupled MAP diagram, including: calibrating a four-layer coupled MAP diagram covering all operating conditions through real vehicle testing, with each MAP diagram being two-dimensional and nested within each other: First layer: Suspension height Δh - vehicle speed v maps to basic power assist gain coefficient k1; Second layer: Lateral acceleration ay-load state m mapping dynamic correction coefficient k2; Third layer: Road surface adhesion coefficient μ-king pin back tilt angle γ mapped to road surface geometric correction coefficient k3; Fourth layer: Steering wheel angle θsw - steering shaft tilt σ mapped to geometric correction coefficient k4; The final total boost gain coefficient k = k1 × k2 × k3 × k4.

[0031] Piecewise nonlinear interpolation includes: dividing each MAP map according to vehicle driving conditions into: Low speed range: v≤30km / h; Medium speed range: 30km / h <v≤80km / h; High-speed section: v>80km / h; Each segment employs quadratic polynomial nonlinear interpolation to make the power assist gain more closely match the nonlinear characteristics of actual steering resistance as parameters change; The interpolation slope constraint is ≤0.05 / ms.

[0032] Third embodiment; This invention provides a third embodiment of a method for adjusting steering assist based on suspension height, which is a further improvement on the first or second embodiment described above. The identical parts will not be repeated here, and it also includes: The dynamic geometry parameters of the kingpin are adjusted in the following way: The suspension ECU calculates the dynamic offset of the kingpin caster angle γ and the steering shaft tilt σ in real time based on the collected control arm angle. Through the air suspension actuator (inflation / deflation valve, control arm micro-adjuster), the kingpin caster trail is controlled within the first distance range of -10mm to +5mm and the steering shaft tilt is controlled within the first angle range of -1° to +3°, thereby reducing the geometric impact of suspension height changes on the steering system from the source. Fourth embodiment; This invention provides a third embodiment of a method for adjusting steering assist based on suspension height, which is a further improvement based on any of the first to third embodiments described above. The identical parts will not be repeated. It also includes: The steps for bidirectional synchronization of suspension and EPS include: while adjusting the suspension height and kingpin dynamic geometry parameters, the suspension ECU sends a pre-compensation command to the EPS ECU via the CAN FD bus. The EPS ECU adjusts the power assist gain in advance to achieve synchronous action of suspension geometry adjustment and power assist torque compensation, avoiding compensation lag. The EPS ECU feeds back the working status of the steering system (power steering motor load, steering wheel operation status) to the suspension ECU in real time. The suspension ECU then dynamically adjusts the suspension damping based on the feedback, achieving two-way coordination.

[0033] Fifth embodiment; This invention provides an EPS dynamic power steering adjustment system, which is used in any one of the adaptive suspension height steering assist methods described in the first to third embodiments, comprising: a distributed multi-sensor redundancy group, a suspension ECU, an EPS ECU, a CAN FD bus, an air suspension actuator, and an EPS power steering motor; The distributed multi-sensor redundancy group is connected to the suspension ECU and EPS ECU via CAN FD bus; The suspension ECU is connected to the air suspension actuator to collect suspension height and control arm angle signals, calculate kingpin dynamic geometric parameters, and control the air suspension actuator. The EPS ECU is connected to the EPS booster motor and is used to receive multi-dimensional parameters, run a piecewise nonlinear compensation model and a multi-dimensional coupled MAP graph interpolation algorithm, and output control signals to the EPS booster motor.

[0034] The distributed multi-sensor redundancy group includes a suspension height sensor, a control arm angle sensor, a vehicle speed sensor, a steering wheel torque sensor, a steering wheel angle sensor, an ESP inertial measurement unit, and a tire pressure sensor.

[0035] Unless otherwise defined, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. It will also be understood that, unless explicitly defined herein, terms such as those defined in a general dictionary shall be interpreted as having the meaning consistent with their meaning in the relevant field context, and not as having an idealized or overly formal meaning.

[0036] The present invention has been described in detail above through specific embodiments and examples, but these are not intended to limit the invention. Many modifications and improvements can be made by those skilled in the art without departing from the principles of the invention, and these should also be considered within the scope of protection of the present invention.

Claims

1. An adaptive suspension height steering assist method, implemented based on an EPS electronic power steering system, characterized in that, Includes the following steps: 1) Real-time acquisition of adaptive compensation calculation parameters, which are then filtered and normalized to establish a piecewise nonlinear compensation model; Adaptive compensation parameters include: Vehicle suspension height change Δh, steering wheel torque signal, steering wheel angle θsw, driving speed v, road surface adhesion coefficient, vehicle lateral acceleration, kingpin dynamic geometric parameters, and vehicle load state dynamic parameters; 2) Establish a piecewise nonlinear compensation model with multi-parameter coupling based on the acquired parameters, including: The relationship between the driver's hand torque Td and the basic torque Ta of the power steering motor is as follows: Td=(Tr-Ta×i×η) / G;Tr is the steering resistance torque, i is the reduction ratio, η is the transmission efficiency, and G is the steering transmission ratio; The formula for calculating the change in steering ratio ΔG caused by the change in suspension height Δh is: ΔG / G≈k×Δh×sin(α); k is the suspension stiffness coefficient, and α is the kingpin inclination angle; Based on the road adhesion coefficient μ, lateral acceleration ay, kingpin dynamic geometric parameter γ / σ, and load state m as correction factors, the steering resistance torque Tr is dynamically corrected. The correction formula is as follows: Trcorr=Tr×[1+kμ×(1−μ)+kay⋅ay+kγ×∣Δγ∣+km×Δm]; kμ, kay, kγ, and km are the correction coefficients calibrated on the actual vehicle, Δγ is the dynamic offset of the kingpin caster angle, and Δm is the load change. The final output torque of the boost motor is: Tacomp = Tabase × f(Δh,v,ay,m) × kμ × kσ; Tabase is the basic assist torque of EPS, f(Δh,v,ay,m) is the four-dimensional coupling compensation function, and kσ is the steering shaft tilt correction coefficient.

2. The adaptive suspension height steering assist method according to claim 1, characterized in that, Also includes: The final total boost gain coefficient is determined by querying the multidimensional coupled MAP graph for boost compensation, and then constrained by piecewise nonlinear interpolation.

3. The adaptive suspension height steering assist method according to claim 2, characterized in that: Constructing a four-layer multidimensional coupled MAP diagram, including: calibrating a four-layer coupled MAP diagram covering all operating conditions through real vehicle testing, with each MAP diagram being two-dimensional and nested within each other: First layer: Suspension height Δh - vehicle speed v maps to basic power assist gain coefficient k1; Second layer: Lateral acceleration ay-load state m mapping dynamic correction coefficient k2; Third layer: Road surface adhesion coefficient μ-king pin back tilt angle γ mapped to road surface geometric correction coefficient k3; Fourth layer: Steering wheel angle θsw - steering shaft tilt σ mapped to geometric correction coefficient k4; The final total boost gain coefficient k = k1 × k2 × k3 × k4.

4. The adaptive suspension height steering assist method according to claim 3, characterized in that, Piecewise nonlinear interpolation includes: dividing each MAP map according to vehicle driving conditions into: Low speed range: v≤30km / h; Medium speed range: 30km / h <v≤80km / h; High-speed section: v>80km / h; Each segment employs quadratic polynomial nonlinear interpolation to make the power assist gain more closely match the nonlinear characteristics of actual steering resistance as parameters change.

5. The adaptive suspension height steering assist method according to claim 4, characterized in that... The interpolation slope constraint is ≤0.05 / ms.

6. The adaptive suspension height steering assist method according to claim 1, characterized in that... : The dynamic geometry parameters of the kingpin are adjusted in the following way: The suspension ECU calculates the dynamic offset of the kingpin caster angle γ and the steering shaft tilt σ in real time based on the collected control arm angle. Through the air suspension actuator (inflation / deflation valve, control arm micro-adjuster), the kingpin caster trail is controlled within the first distance range of -10mm to +5mm, and the steering shaft tilt is controlled within the first angle range of -1° to +3°.

7. The adaptive suspension height steering assist method according to claim 6, characterized in that, Also includes: The steps for suspension-EPS bidirectional synchronization include: while adjusting the suspension height and kingpin dynamic geometry parameters, the suspension ECU sends a pre-compensation command to the EPS ECU via the CAN FD bus, and the EPS ECU adjusts the power assist gain in advance; The EPS ECU feeds back the working status of the steering system to the suspension ECU in real time. The suspension ECU then dynamically adjusts the suspension damping based on the feedback, achieving two-way coordination.

8. An EPS dynamic power steering adjustment system, used to implement the adaptive suspension height steering assist method described in any one of 1-7, characterized in that, Includes: distributed multi-sensor redundancy group, suspension ECU, EPS ECU, CAN FD bus, air suspension actuator, EPS booster motor; The distributed multi-sensor redundancy group is connected to the suspension ECU and EPS ECU via CAN FD bus; The suspension ECU is connected to the air suspension actuator to collect suspension height and control arm angle signals, calculate kingpin dynamic geometric parameters, and control the air suspension actuator. The EPS ECU is connected to the EPS booster motor and is used to receive multi-dimensional parameters, run a piecewise nonlinear compensation model and a multi-dimensional coupled MAP graph interpolation algorithm, and output control signals to the EPS booster motor.

9. The EPS dynamic assist adjustment system according to claim 8, characterized in that: The distributed multi-sensor redundancy group includes a suspension height sensor, a control arm angle sensor, a vehicle speed sensor, a steering wheel torque sensor, a steering wheel angle sensor, an ESP inertial measurement unit, and a tire pressure sensor.